Flashing is a piece of metal installed beneath shingles on the exterior of a building used to prevent water from entering the building. Current teaching in the field requires the removal of shingles before the installation of flashing or installing the flashing before the shingles are installed in the first instance.
The present invention teaches a manner of installing flashing beneath exterior shingles without first removing the shingles, creating a water resistant barrier in a much faster and efficient manner.